Decimation is a scary, realistic and open-world zombie survival Mod, in which players (or Survivors) have one task: Survive in this zombie-ridden world for as long as possible! Over time, players will experience powerful moments and events whilst emerging in this mods gameplay. You will make friends and foe, join as a team or betray your squad over greed. Every descision made in Decimation counts towards your survival.

Last Days Resource Pack (1.7.10) is a 3-rd party Resource Pack created by DerekSmith (xemnasvii). The original Resource Pack thread can be found here or here.

Why does it need to be for 1.12.2? It's basically a game of it's own, so the version it's for shouldn't matter. If 1.7.10 forge isn't working for you, try getting the game(Decimation) via Technic.

Also, making it for 1.12.2 would mean him basically rewriting the entire game from scratch, which would take forever, and then he'd be stuck not being able to add new content until it's done. Which would damage motivation a ton, mostly killing the project as a whole. Having been a game developer, I know this first hand.